At present, various ways of excavating coal mine tunnels include mainly continuous mining, continuous excavating and comprehensive excavating; the supporting ways is the combined supporting of anchor bolts, anchor cables, trimming beams and anchor nets. During etting of roof anchor bolts and anchor cables mono-drills or a crawler-type drilling machines are used. For example, a self-propelled roof bolter which is disclosed in a Chinese patent No. 200420091861.7 comprises two drilling devices, two advanced supports, a crawler-type moving mechanism, a slipway for the integral horizontal movement of the drilling devices and a platform, wherein the moving mechanism is driven by a hydraulic motor and is provided on the rack thereof with an anchor bolter platform equipped with two hydraulic cylinder type advanced supports on both sides at the front end of the platform, two gantry drilling devices following the two hydraulic cylinder type advanced supports, a slipway for the horizontal movement of the whole drilling devices which are arranged on the slipway, an electric control cabinet, a hydraulic pumping unit and a material box and the like. Each drilling device comprises a pillar, a device for horizontal movement of the gantry, a gantry-rotating device, an oil cylinder for forward and backward swinging of the gantry, a trunnion, the gantry and a drilling motor unit mounted on the gantry which in turn by means of the trunnion and the cylinder for swinging forward and backward of the gantry is articulated on the gantry-rotating device mounted on the device for horizontal movement of the gantry which is fixed on the pillar arranged on the slipway for the integral horizontal movement.
Hand-held pneumatic drills are used both in setting of Side wall anchor bolts and Side wall anchor cables which has the following problems:    (1) The excavated tunnel has a small cross section: about 15 M2 generally, and a scaffolding is needed for setting roof and/or Side wall anchor bolts and anchor cables if the height of the tunnel is over 2 m.    (2) The operation can not be mechanized: setting of roof anchor bolts and anchor cables in the mining tunnels has been substantially mechanized in the process of continuous mining and continuous excavating, but has still been manually operated by means of the mono-drill in the process of comprehensive excavating, however for setting of Side wall anchor bolts and anchor cables in whatever mining or excavating process man still uses hand-held pneumatic drill, in which the push force for drilling hole comes from the arms of workers, which results strong labor work and un-ensured quality of the setting of the side walls anchor bolts and anchor cables.    (3) The setting speed is slow: plenty of time is needed for setting and the dismounting of the scaffoldings when the cross section is over 2 m.    (4) The efficiency is low: due to too many drilled holes and too many labors.    (5) The safety is difficult to control: due to the operation at high altitude and the poor environment.